i'm also getting this WARN_ON() from e1000:
BUG: at drivers/pci/msi.c:611 pci_enable_msi()
[<c01061bd>] show_trace_log_lvl+0x19/0x2e
[<c01062b6>] show_trace+0x12/0x14
[<c01062cc>] dump_stack+0x14/0x16
[<c024fcc4>] pci_enable_msi+0x6d/0x203
[<c02b709e>] e1000_request_irq+0x2e/0xe2
[<c02bb742>] e1000_resume+0x7f/0xef
[<c0249a68>] pci_device_resume+0x1a/0x44
[<c02b39ec>] resume_device+0xf7/0x16f
[<c02b3adb>] dpm_resume+0x77/0xcb
[<c02b3b69>] device_resume+0x3a/0x51
[<c014e669>] enter_state+0x193/0x1bb
[<c014e712>] state_store+0x81/0x97
[<c01b68bc>] subsys_attr_store+0x20/0x25
[<c01b6feb>] sysfs_write_file+0xce/0xf6
[<c017e16b>] vfs_write+0xb1/0x13a
[<c017e899>] sys_write+0x3d/0x61
[<c0105220>] syscall_call+0x7/0xb
seems harmless because it seems to work fine.